He told the children a morality tale intended to reinforce the value of rules.
There was a huge train accident in Germany, two trains collided with each other. The trains were on the same track. Eight people died, hundreds were injured, many lost limbs. This kind of thing doesn’t happen in Germany. Germany is the land of rules, with primary, secondary and tertiary safety systems in case something does not go according to the rules. Do they need to add an additional safety system?
No, they don’t need a quaternary safety system because it turns out a supervisor turned OFF the existing safety systems. He wanted to allow a slow moving freight train to make up lost time. The net result of this action was eight lives lost, grievous injuries, and for the supervisor some serious jail time. His will be the example of why people have to follow rules.
Let that be a lesson to you kids: Don’t let slow moving freight trains warp your judgment.